Ultrahigh discharge energy density (W_dis = 10.5 J cm⁻³) and efficiency (η = 87%) have been obtained in doped BiFeO₃–BaTiO₃ ceramic multilayers by achieving an electrically rather than chemically homogeneous microstructure. Back scattered scanning and transmission electron microscopy combined with energy dispersive X-ray spectroscopy mapping of (0.7 − x)BiFeO₃–0.3BaTiO₃–xNd(Zn_0.5Zr_0.5)O₃ (0.05 ≤ x ≤ 0.10) ceramics revealed a core–shell grain structure which switched from a bright to dark contrast as x increased. Compositions with x = 0.08 were at the point of cross over between these two manifestations of core–shell contrast. Dielectric measurements together with the absence of macrodomains in diffraction contrast TEM images suggested that compositions with x = 0.08 exhibited relaxor behaviour within both the core and shell regions. Impedance spectroscopy demonstrated that, despite being chemical dissimilar, the grains were electrically homogeneous and insulating with little evidence of conductive cores. Multilayers of x = 0.08 had enhanced breakdown strength, E_BDS > 700 kV cm⁻¹ and a slim hysteresis loop which resulted in large W_dis and high η which were temperature stable to <15% from 25 to 150 °C.

The piezoelectric properties of lead zirconate titanate [Pb(Zr,Ti)O ₃ or PZT] ceramics could be enhanced by fabricating textured ceramics that would align the crystal grains along specific orientations. We present a seed-passivated texturing process to fabricate textured PZT ceramics by using newly developed Ba(Zr,Ti)O ₃ microplatelet templates. This process not only ensures the template-induced grain growth in titanium-rich PZT layers but also facilitates desired composition through interlayer diffusion of zirconium and titanium. We successfully prepared textured PZT ceramics with outstanding properties, including Curie temperatures of 360°C, piezoelectric coefficients d ₃₃ of 760 picocoulombs per newton and g ₃₃ of 100 millivolt meters per newton, and electromechanical couplings k ₃₃ of 0.85. This study addresses the challenge of fabricating textured rhombohedral PZT ceramics by suppressing the otherwise severe chemical reaction between PZT powder and titanate templates.

An electrostatic capacitor has been widely used in many fields (such as high pulsed power technology, new energy vehicles, etc.) due to its ultrahigh discharge power density. Remarkable progress has been made over the past 10 years by doping ferroelectric ceramics into polymers because the dielectric constant is positively correlated with the energy storage density. However, this method often leads to an increase in dielectric loss and a decrease in energy storage efficiency. Therefore, the way of using a multilayer structure to improve the energy storage density of the dielectric has attracted the attention of researchers. Although research on energy storage properties using multilayer dielectric is just beginning, it shows the excellent effect and huge potential. In this review, the main physical mechanisms of polarization, breakdown and energy storage in multilayer structure dielectric are introduced, the theoretical simulation and experimental results are systematically summarized, and the preparation methods and design ideas of multilayer structure dielectrics are mainly described. This article covers not only an overview of the state‐of‐the‐art advances of multilayer structure energy storage dielectric but also the prospects that may open another window to tune the electrical performance of the electrostatic capacitor via designing a multilayer structure.

The (Nb + In) co-doped TiO₂ ceramics were synthesized by conventional solid-state sintering (CSSS) and spark plasma sintering (SPS) methods. The phases and microstructures were studied by X-ray diffraction, Raman spectra, field-emission scanning electron microscopy and transmission electron microscopy, indicating that both samples were in pure rutile phase while showing significant difference in grain size. The dielectric and I–V behaviors of SPS and CSSS samples were investigated. Though both possess colossal permittivity (CP), the SPS samples exhibited much higher dielectric permittivity/loss factor and lower breakdown electric field when compared to their CSSS counterparts. To further explore the origin of CP in co-doped TiO₂ ceramics, the I–V behavior was studied on single grain and grain boundary in CSSS sample. The nearly ohmic I–V behavior was observed in single grain, while GBs showed nonlinear behavior and much higher resistance. The higher dielectric permittivity and lower breakdown electric field in SPS samples, thus, were thought to be associated with the feature of SPS, by which reduced space charges and/or impurity segregation can be achieved at grain boundaries. The present results support that the grain boundary capacitance effect plays an important role in the CP and nonlinear I–V behavior of (Nb + In) co-doped TiO₂ ceramics.